Tartarus: A relativistic Green's function quantum average atom code

Gill, Nathanael Matthew; Starrett, Charles Edward

doi:10.1016/j.hedp.2017.06.002

Title: Tartarus: A relativistic Green's function quantum average atom code

Full Record
Other Related Research

Abstract

A relativistic Green’s Function quantum average atom model is implemented in the Tartarus code for the calculation of equation of state data in dense plasmas. We first present the relativistic extension of the quantum Green’s Function average atom model described by Starrett [1]. The Green’s Function approach addresses the numerical challenges arising from resonances in the continuum density of states without the need for resonance tracking algorithms or adaptive meshes, though there are still numerical challenges inherent to this algorithm. We discuss how these challenges are addressed in the Tartarus algorithm. The outputs of the calculation are shown in comparison to PIMC/DFT-MD simulations of the Principal Shock Hugoniot in Silicon. Finally, we also present the calculation of the Hugoniot for Silver coming from both the relativistic and nonrelativistic modes of the Tartarus code.

Authors:

^[1];

^[1]

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:: Wed Jun 28 00:00:00 EDT 2017

Research Org.:: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1369177

Alternate Identifier(s):: OSTI ID: 1550383

Report Number(s):: LA-UR-17-22290
Journal ID: ISSN 1574-1818

Grant/Contract Number:: AC52-06NA25396; 20150656ECR

Resource Type:: Accepted Manuscript

Journal Name:: High Energy Density Physics

Additional Journal Information:: Journal Volume: 24; Journal ID: ISSN 1574-1818

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Average Atom, Warm Dense Matter, Equation of State

Citation Formats


                    Gill, Nathanael Matthew, and Starrett, Charles Edward. Tartarus: A relativistic Green's function quantum average atom code.  United States: N. p., 2017. 
Web.  doi:10.1016/j.hedp.2017.06.002.

Copy to clipboard


                    Gill, Nathanael Matthew, & Starrett, Charles Edward. Tartarus: A relativistic Green's function quantum average atom code.  United States.  https://doi.org/10.1016/j.hedp.2017.06.002

Copy to clipboard


                    Gill, Nathanael Matthew, and Starrett, Charles Edward. Wed .  
"Tartarus: A relativistic Green's function quantum average atom code".  United States.  https://doi.org/10.1016/j.hedp.2017.06.002.  https://www.osti.gov/servlets/purl/1369177.

Copy to clipboard


                    
@article{osti_1369177,

  title        = {Tartarus: A relativistic Green's function quantum average atom code},

  author       = {Gill, Nathanael Matthew and Starrett, Charles Edward},

  abstractNote = {A relativistic Green’s Function quantum average atom model is implemented in the Tartarus code for the calculation of equation of state data in dense plasmas. We first present the relativistic extension of the quantum Green’s Function average atom model described by Starrett [1]. The Green’s Function approach addresses the numerical challenges arising from resonances in the continuum density of states without the need for resonance tracking algorithms or adaptive meshes, though there are still numerical challenges inherent to this algorithm. We discuss how these challenges are addressed in the Tartarus algorithm. The outputs of the calculation are shown in comparison to PIMC/DFT-MD simulations of the Principal Shock Hugoniot in Silicon. Finally, we also present the calculation of the Hugoniot for Silver coming from both the relativistic and nonrelativistic modes of the Tartarus code.},

  doi          = {10.1016/j.hedp.2017.06.002},

  journal      = {High Energy Density Physics},

  number       = ,

  volume       = 24,

  place        = {United States},

  year         = {Wed Jun 28 00:00:00 EDT 2017},

  month        = {Wed Jun 28 00:00:00 EDT 2017}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (Publisher)

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1016/j.hedp.2017.06.002

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 8 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

Wide ranging equation of state with Tartarus: A hybrid Green’s function/orbital based average atom code

Journal Article Starrett, Charles Edward ; Gill, Nathanael Matthew ; Sjostrom, Travis ; ... - Computer Physics Communications

Average atom models are widely used to make equation of state tables and for calculating other properties of materials over a wide range of conditions, from zero temperature isolated atom to fully ionized free electron gases. The numerical challenge of making these density functional theory based models work for any temperature, density or nuclear species is formidable. Here we present in detail a hybrid Green’s function/orbital based approach that has proved to be stable and accurate for wide ranging conditions. Algorithmic strategies are discussed. In particular the decomposition of the electron density into numerically advantageous parts is presented and amore »« less
Cited by 16
https://doi.org/10.1016/j.cpc.2018.10.002

Full Text Available
A Green's function quantum average atom model

Journal Article Starrett, Charles Edward - High Energy Density Physics

A quantum average atom model is reformulated using Green's functions. This allows integrals along the real energy axis to be deformed into the complex plane. The advantage being that sharp features such as resonances and bound states are broadened by a Lorentzian with a half-width chosen for numerical convenience. An implementation of this method therefore avoids numerically challenging resonance tracking and the search for weakly bound states, without changing the physical content or results of the model. A straightforward implementation results in up to a factor of 5 speed-up relative to an optimized orbital based code.
Cited by 12
https://doi.org/10.1016/j.hedp.2015.05.001

Full Text Available
Variational-average-atom-in-quantum-plasmas (VAAQP) code and virial theorem: Equation-of-state and shock-Hugoniot calculations for warm dense Al, Fe, Cu, and Pb

Journal Article Piron, R ; Blenski, T - Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print)

The numerical code VAAQP (variational average atom in quantum plasmas), which is based on a fully variational model of equilibrium dense plasmas, is applied to equation-of-state calculations for aluminum, iron, copper, and lead in the warm-dense-matter regime. VAAQP does not impose the neutrality of the Wigner-Seitz ion sphere; it provides the average-atom structure and the mean ionization self-consistently from the solution of the variational equations. The formula used for the electronic pressure is simple and does not require any numerical differentiation. In this paper, the virial theorem is derived in both nonrelativistic and relativistic versions of the model. This theoremmore »« less
https://doi.org/10.1103/PHYSREVE.83.026403
Equation of state for 304L stainless steel

Journal Article Sjostrom, Travis - AIP Conference Proceedings

Here, a new equation of state for 304L stainless steel has been constructed and entered in the Los Alamos National Laboratory SESAME database with material ID 4273. The equation of state is based on a multiphase approach. The solid and liquid phases were fitted to available experimental data for thermal expansion, heat capacity, and shock Hugoniot, as well as to data from density functional theory calculations of the cold curve and quantum molecular dynamics of the liquid regime. The electronic thermal contribution over the entire equation of state range is based on Tartarus (Green’s functions) average atom calculations. For thismore »« less
https://doi.org/10.1063/12.0020364
Equation of state and shock compression of warm dense sodium—A first-principles study

Journal Article Zhang, Shuai ; Driver, Kevin P. ; Soubiran, Francois ; ... - Journal of Chemical Physics

As one of the simple alkali metals, sodium has been of fundamental interest for shock physics experiments, but knowledge of its equation of state (EOS) in hot, dense regimes is not well known. By combining path integral Monte Carlo (PIMC) results for partially ionized states at high temperatures and density functional theory molecular dynamics (DFT-MD) results at lower temperatures, we have constructed a coherent equation of state for sodium over a wide density-temperature range of 1.93-11.60 g/cm³ and 10³–1.29×10⁸ K. We find that a localized, Hartree-Fock nodal structure in PIMC yields pressures and internal energies that are consistent with DFT-MDmore »« less
Cited by 29
https://doi.org/10.1063/1.4976559

Full Text Available

Similar Records